Ever since he was a young boy, JB (Jack Black) wanted to follow the path of heavy metal, but when demonstrating his talents to his pious, fundamentalist Christian family they were not well received, especially by his father (Meat Loaf) who took his belt and thrashed him for what he regarded as blasphemy, then tore down the rock posters from JB's bedroom walls. However, when he left and slammed the door, he had forgotten one poster of Dio, which came alive and spoke to the young upstart in his hour of need. Dio told him to go to Hollywood, and by the time he had found the right Hollywood he had grown up...
Jack Black and Kyle Gass's Tenacious D are regarded as something of a joke by many, but they always give the impression of being sincere about their love of rock, so even if the songs are more humorous than most in the field (intentionally humorous at any rate), they do know how to have a good time with their chosen passion. The duo wrote their debut film, The Pick of Destiny, along with director Liam Lynch, rendering a road movie with a Wizard of Oz message about having what it took to succeed all along mixed with a Topkapi heist and an ending out of the Charlie Daniels Band song "The Devil Went Down to Georgia", only with guitars instead of violins.
Acoustic guitars, that is, as for some reason Tenacious D eschew the simple pleasures of getting down to it with an electric guitar in favour of the non-plugged in kind. Why this is is never made clear, as all the axe-men they consider heroes use the electric instrument where JB and KG prefer to keep it basic. As for how they meet up in the movie, JB arrives in Hollywood and spies KG busking; immediately impressed he goes over to introduce himself, but KG is having none of it and rejects his newest (and possibly only) fan. JB will not be deterred, however, and before long is a hanger on who hopes to be moulded into a rock god.
In a Karate Kid-style development, KG becomes JB's mentor, although we are suspicious that he isn't as experienced and successful as he claims to be, and sure enough when JB tries out at an audition in the apartment they now share, it all goes horribly wrong and the hopeful accidentally smashes his beloved guitar - a heart-rending moment. Really. Then it goes from bad to worse when KG is revealed to be existing on cheques from his parents, money which has just dried up. A ray of hope shines into their lives, and KG undergoes a complete personality change into the bargain, when JB finds out he has bought him his own guitar.
And with all that in the first half hour, they certainly pack in the plotting. After this lengthy preamble, the story begins properly, as Tenacious D, named after the complimentary birthmarks they share, start at the top appearing at an amateur night. Well, it's not the top at all, but they have high hopes and when they notice that all the great rock guitarists use the same pick, they realise they're onto something big. Ben Stiller is just one celebrity cameo among many, here explaining the pick's history as the tooth of Satan, passed down through history and now residing in a rock museum where JB and KG must steal it. Along the way JB meets the Sasquatch played by John C. Reilly ("Sasquatch researcher" in the credits) while tripping on mushrooms, and there's a car chase that strangely doesn't jar with the relaxed style of the rest of the film. As a tale of male bonding through rock, it should strike a chord with many fans, but is more amusing and good natured than roar with laughter funny.